Land ocean carbon transfer (LOCATE)

Completed project

Project start: April 2017  |  Project end: March 2022
Funder: NERC Cross-centre National Capability - led by NOC
Principal Investigator: Dr Andy Rees
Other participants from PML: Dr Andy Rees, Dr Glen Tarran, Dr Luca Polimene, Dr Vassilis Kitidis, E. Malcolm S. Woodward, Ian Brown, Jerry Blackford, John Stephens, Lisa Al-Moosawi

Human activities such as land clearance and the burning of fossil fuels have increased atmospheric carbon dioxide levels by about 40% in the last 250 years, with most of this increase occurring since the Second World War. This has caused a measurable increase in our temperature, with many of the warmest years on record occurring in the last decade.

For this reason our interest is now firmly focused on other natural parts of the carbon cycle, in particular other reservoirs of carbon which are currently locked away from the atmosphere but which might enter the atmosphere as climate changes. One key pool is soil carbon – soils across the globe contain about 4 times as much carbon as the fossil fuel carbon which to date has entered the atmosphere via combustion, with this pool being largest at high latitudes such as northern Scotland.

The British pool of soil carbon is a large element of our ‘natural capital’ – the value that the ecosystem represents to us. It is so large that restoring some damaged elements of it, such as upland peat bogs, would probably save us 570 million pounds over the next 40 years in carbon values alone. Each year some of this leaches into rivers and streams, with the concentration of carbon in rivers gradually increasing in Britain and Europe. As this material gets into estuaries and coastal waters some of it gets returned to the atmosphere when bacteria use it to grow or when it’s destroyed by sunlight, some is buried and some enters the open ocean. We don’t understand what controls these various processes, so aren’t currently in a position to say how they will change into the future.

Impact

The LOCATE project will establish the current status of our peatland stocks (how much soil carbon is getting into our rivers and estuaries), and then determine what happens to this material in our estuaries (including measuring the key processes). Based on this we will do some accurate up to date carbon accounts for the GB landmass and also produce some simple mathematical equations describing what happens to soil organic matter in our rivers and estuaries. These equations will then be embedded into a much larger model of the Earth System so that we can begin to answer questions about the long term fate of the soil organic carbon pool over the next 50 or 100 years.